1) Field of the Invention
The present invention relates to a technology for calculating a moving-image correction coefficient that is applied to a frame of a moving-image, and for correcting the moving-image by applying the moving-image correction coefficient calculated.
2) Description of the Related Art
In order to improve image quality of moving-images acquired by video cameras, conventionally, various corrections such as gamma correction, color balance correction, and chroma saturation correction are made. The correction is normally made for each frame of a moving-image, but since a calculation amount becomes voluminous, a method in which a calculation amount can be reduced is proposed.
For example, Japanese Patent Application Laid-Open No. 2002-77723 discloses a moving-image processing apparatus that calculates correction-coefficients only when a scene change such that an image greatly changes is detected, and uses the correction-coefficients until a next scene change is detected so as to reduce a calculation amount.
Japanese Patent Application Laid-Open No. 2002-262303 discloses an image processing apparatus that calculates correction-coefficients when a scene is changed or when the number of the frames in a moving-image is counted, and the counted value exceeds a predetermined threshold.
However, in the conventional techniques described above, since the same correction-coefficients are used until the scene change is detected or the number of frames exceeds a certain value, the improvement of the image quality cannot be really expected.
In the technique disclosed in the Japanese Patent Application Laid-Open No. 2002-262303, a predetermined threshold at the time of comparing the number of frames with a counted value is reduced, so that the correction-coefficients may be calculated with a shorter time interval. However, a calculation amount of the correction-coefficients becomes large.